1. Field of the Invention
The present invention relates to: an exposure operation evaluation method for an exposure apparatus for adjusting and controlling an exposure operation by measuring a printing result of a predetermined evaluation pattern which has been printed on a substrate by the exposure operation; and a manufacturing method for semiconductor device for manufacturing a semiconductor device by using the adjusted and controlled exposure apparatus based on the evaluation result obtained by the exposure operation evaluation method for the exposure apparatus.
2. Description of the Related Art
When factories for manufacturing semiconductor elements (e.g., ultra large scale integrated circuit) form a pattern (e.g., circuit pattern) on a substrate, they mainly print on the substrate the pattern (e.g., circuit pattern), which has been drawn on a reticle, by using a reduced projection exposure apparatus through a projection lens, perform a step of forming the pattern such as the circuit pattern on the substrate a plurality of times so as to manufacture a semiconductor element in a laminated structure on the substrate. This exposure step has been increasingly performed by using exposure apparatuses, which have different accuracy from each other, for an exposure step in each different manufacturing step during the process of manufacturing one type of semiconductor device in consideration of processing accuracy and manufacturing cost of each pattern to be formed.
For example, for each semiconductor device, formed according to a new generation rule, with its processing line width being reduced, process construction of all layers for a semiconductor element to be manufactured by newly utilizing exposure apparatuses whose accuracy has been improved in each factor does not satisfy the manufacturing cost. Thus, a combination of exposure apparatuses which were used in each generation before the previous generation and new exposure apparatuses which can achieve a required new technique with excellent accuracy is often used to construct a process which achieves a rule for a new generation. Accordingly, in a process of manufacturing one type of a semiconductor device, exposure apparatuses with different functions and performance from each other have been increasingly used for the exposure process of each processed layer.
For exposure apparatuses in each generation, in order to obtain the resolution which is required in each generation along with the miniaturization of a circuit pattern, exposure light is caused to be short-wavelengthened. As exposure light which has been short-wavelengthened, for example, i ray (wavelength 365 nm) from mercury lamp, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm) have been put into practice, and exposure apparatuses which use further short-wavelengthened F2 (wavelength 157 nm) excimer laser, electronic beam drawing technology, EUV (wavelength 13 nm) light and the like have been pursued.
When a pattern (e.g. circuit pattern) on a reticle is reduced-projected onto a substrate by using the light source thereof, in exposure apparatuses (e.g., full-field-type (stepper) and scanning-type (scanner) which have been used in each generation), a processing technique and a lens material for a reduced projection lens, a table driving control accuracy, an exposure method, an exposure field area, a reduced projection magnification, an alignment accuracy and the like are different between each exposure apparatus.
When each layer is formed, for example, a structure is being established such that exposure in each step is performed using the following so-called mix and match method: (i) a scanning-type reduced projection exposure apparatus (scanner) is used for exposure of a critical layer which requires high alignment accuracy; (ii) a full-field-type reduced projection exposure apparatus (stepper), which has been used for the critical layer in the previous generation, is used for exposure of a sub-critical layer which does not require the alignment accuracy as high as that for the critical layer but requires a certain degree of alignment accuracy; and (iii) a full-field-type reduced projection exposure apparatus (stepper), which was used in the generations before the previous generation, or a full-field-type reduced projection exposure apparatus (stepper), which has a low-reduced magnification and is intended for improving the throughput, is used for exposure of a rough layer.
When a first layer is exposed to light on a semiconductor substrate, accuracy relating to alignment of a printed pattern is not normally measured. This is because it is considered that a variety of accuracy of the exposure apparatus, for example, stage stepping accuracy, reduced projection magnification control accuracy, reticle rotation accuracy, shot alignment accuracy, distortion, stage synchronization accuracy between an original plate and a substrate by the scanning-type reduced projection exposure apparatus (scanner) and the like are regularly measured, managed and corrected, and the results which are used in an allowable range are reflected.
Additionally, when the exposure apparatus for the first layer is the full-field-type reduced projection exposure apparatus (stepper) and the exposure apparatus for the second layer and its subsequent layers is the scanning-type reduced projection exposure apparatus (scanner), and the result of alignment for the second layer is to be improved, then the number of items of linear components to be corrected which can be corrected by the scanning-type reduced projection exposure apparatus (scanner) is the same as that by the full-field-type reduced projection exposure apparatus (stepper) and furthermore there are other items to be corrected other than them. Therefore, correction can be performed with high accuracy. Alternatively, as another example, when the exposure apparatus for the first layer is the full-field-type reduced projection exposure apparatus (stepper) and the exposure apparatus for the second layer and its subsequent layers is also the full-field-type reduced projection exposure apparatus (stepper), then it is possible to improve the alignment result by conducting a setting (grouping) of an exposure apparatus group in which each exposure apparatus has a similar misalignment tendency for distortion to each other.
Reference 1 discloses a technology that the position of a destroyed pattern image such as in thin line portion is obtained as a printed error of an evaluation pattern which has been printed on a substrate (wafer) while moving (scanning) an original plate (reticle) and the substrate in synchronization by using the scanning-type reduced projection exposure apparatus (scanner) so as to evaluate the exposure operation with excellent accuracy at high speed. Based on this evaluation result, an exposure condition of the scanning-type reduced projection exposure apparatus (scanner) is evaluated, and the evaluation result is then fed back in order to adjust and control the scanning-type reduced projection exposure apparatus (scanner).
Reference 2 discloses an alignment and exposure method for calculating the position of a particular exposure area (hereinafter, referred to as “shot”) among shots, which have been printed on a substrate (wafer), relative to other shots by employing a mix and match method for exposing mask patterns one above another on the substrate by using two exposure apparatuses in which exposure field sizes are different from each other. According to this technology, deformation in the wafer and deformation in the shot can be learned with the minimum number of alignment, and the alignment between an upper layer and a lower layer can be improved, thereby being able to improve the throughput of the exposure.
[Reference 1] Japanese Laid-Open Publication No. 11-186155
[Reference 2] Japanese Laid-Open Publication No. 11-195596